Despite reducing transportation and handling costs, pelletizing cellulosic biomass would not be cost-effective for ethanol producers, according to a Purdue University study.
Klein Ileleji, an associate professor of agricultural and biological engineering, and Preethi Krishnakumar, a graduate research student, factored the costs and logistical requirements cellulosic ethanol producers would face using different types of biomass - corn grain, corn stover and switchgrass - in both bale and pellet forms.
Their findings, published in the journal Applied Engineering in Agriculture, show that the denser cellulosic pellets would allow ethanol producers to save money by utilizing the same equipment used to transport and handle corn grain that flows using elevators, hoppers and conveyor belts.
But, the pellet-making process causes a nearly 50 percent loss of biomass yield. If two bales of cellulosic biomass are used to create pellets, the pellets only weigh as much as one of the original bales, Ileleji said. This is because as much as 50 percent of the original feedstock could be lost in the pelleting process, according to the study from the West LaFayette, Ind.-based university.